This invention relates to a modular service unit for incorporation or installation in suspended ceilings or false ceilings.
Hitherto, suspended ceilings have been constructed on a basis wherein a grid of frame members or support members, often having a T-bar cross-section, were attached to overhead structures between side walls of a room of a building, and ceiling tiles or panels were then connected to the frame members so as to provide an aesthetic appearance. In the space between the frame members and a top wall or frame of the room were provided air conditioning ducts which were attached to plenum housings which expelled conditioned air into a room from outlets on grilles inclusive of air diffusers located in the ceiling tiles or panels. There were also provided fluorescent light fittings or troffers located at spaced intervals in the suspended ceiling as well as other service facilities such as fire alarm detectors, fire sprinklers, security equipment, speakers and spot light fittings or feature light fittings.
Troffers, when installed in a suspended ceiling were sometimes associated with plenum housings which were to be connected to air conditioning ducts and a first type of conventional service arrangement comprised a single troffer having a housing for one or more fluorescent light tubes whereby there was provided a pair of plenum housings or “air boots” as they are known in the art, wherein each air boot was supported on lower edge portions of the troffer housing and extended upwardly above the top of the troffer housing. Each air boot was interconnected by a hollow duct extending transversely to a longitudinal axis of the troffer housing. One of the air boots was provided with a hollow connection spigot for attachment to an air duct.
Disadvantages of the first type of conventional service arrangement described above was that it could only be efficiently used with a particular type of air diffuser for expulsion of conditioned air into the room. Thus it could only be used in an efficient manner with constant air diffusers and its use with variable air volume diffusers was restricted. It also could not be utilized with other service facilities, e.g., fire alarm detectors, fire sprinklers, speakers, spot light fittings, or feature light fittings, in an efficient manner.
In a second type of conventional service arrangement there was utilized a single light troffer which was located adjacent to an air conditioning apparatus which included a plenum housing, a base flange surrounding a bottom opening in the plenum housing and a connection spigot to an air duct. This second type of service arrangement was disadvantageous because installation was not only time consuming and expensive but it detracted from the overall appearance or aesthetics of a room to which it was installed. Also, like the first type of service arrangement described above, it could not be used in an efficient manner it utilized with other services such as those described above.
Reference may also be made to GB Patent 1 509 259 which refers to a combined illumination and ventilation device which comprises a plurality of profile elements. Each profile element has a reflector having a light tube combined therein. Each profile element also incorporated a trapezoidal channel which enclosed an elongate choke coil associated with the adjacent light tube. The trapezoidal channel is integral with the reflector. There is also provided a duct between each reflector and trapezoidal channel. Each reflector has a pair of integral bottom flanges one of which supports an air control flap which controls flow of air into or out of an adjacent duct.
The structure of GB Patent 1 509 259 is extremely complicated comprising a single modular unit which was the profile element as described above. Each of the profile elements are arranged in a side by side arrangement separated by each duct which has a button gap for entry or exit of air. In this arrangement there was also included a cover plant which interconnected each modular unit. Because of its complicated structure, the profile elements were only designed as a combined lighting and ventilation device and thus could not be adapted to incorporate other service facilities in lieu of ventilation.
Another disadvantage of the structure of GB Patent 1 509 259 was that it could not be utilized in conventional suspended ceilings having a grid of longitudinal T bars and transverse T bars.
Reference may also be made to other prior art references which combine an additional service facility with a lamp device and reference may be made to GB 864894, Japanese Patent Publication 04-188998, DE 3643075, U.S. Pat. No. 5,263,290 and U.S. Pat. No. 6,443,592, all of which suffer from the same disadvantages as GB 1 509 259, i.e., being of complicated construction and not being attachable to conventional suspended ceilings as described above.